Spatial data is collected through various sources: - Surveillance Systems: Public health surveillance systems collect data on disease incidence and prevalence, which can be geocoded to specific locations. - Remote Sensing: Satellite imagery and aerial photography provide environmental data that can be linked to health outcomes. - Geocoding Addresses: Patient addresses from healthcare records can be converted into geographical coordinates for spatial analysis. - Field Surveys: Data on environmental exposures and living conditions can be collected through field surveys and mapped to specific locations.